1. Field of the Invention
The present invention relates to an optical navigation device, and more particularly, to an optical navigation device with automatic magnification adjusting function for enhanced navigation accuracy and a related automatic magnification adjusting method.
2. Description of the Prior Art
Conventional navigation device may utilize a roller mechanism or an optical sensing module to calculate coordinate variation of the navigation device relative to a supporting plane. A roller of the roller mechanism is rotated over the supporting plane by friction force, and dust is easily attached to the roller and decreases its sensitivity or responsiveness. The optical sensing module has an optical transmitter and an optical receiver. Light is emitted from the optical transmitter to project onto the plane, and the optical receiver captures the light reflected from the plane to analyze the coordinate variation due to relative motion between the sensor and object plane. However, an optical transmission path between the optical transmitter and the optical receiver may be varied due to flexion of the medium, which results in error calculation of the coordinate variation.